A young Bill Clinton meets President John F. Kennedy in the Rose Garden on July 26, 1963. Clinton, who was 16 years old at the time, was part of the Arkansas delegation to the American Legion Boys Nation.

President Gerald Ford leaves his Alexandria, Va., home to go to work at the White House the day after he was sworn in. The Nixons' personal belongings had not yet been moved out of the White House living quarters.

President Clinton and South African President Nelson Mandela peer out of the window of Mandela's former cell on Robben Island outside Cape Town, 1998. Mandela spent 18 of his 27 years as a political prisoner in this cell.

Every four years, we elect a president. And every term, the president is joined in the White House by his Cabinet and staff — and followed by a press pool intent on documenting the presidency. For those photographers, portraying the true personality and actions of a leader so protected can be difficult.

In 1921, a group was formed to help make access easier. The White House News Photographers Association (WHNPA) was started by 17 camera and motion-picture photographers who covered the daily activities of the White House.

Initially, WHNPA members were able to negotiate access to many intimate moments — although their heavy equipment made the job difficult. The first photos were made with clunky view cameras that worked poorly indoors in low light. And since shooting a candid shot wasn't easy, restaging scenes was not uncommon.

These days, of course, cameras are lighter and more versatile, but access isn't what it used to be. Candid shots are still hard to get — but now it's because of heightened security.

After combing through 95,000 images in its archives, the WHNPA has put together an exhibit of 78 historic photographs of some of those candid moments; some are well-known, while others have been locked away for decades.

"My favorite image is the one of John F. Kennedy during the presidential campaign sitting in an open-air convertible catching a bunch of bananas," writes WHNPA Treasurer Jon Elswick, who co-curated the exhibit with his wife, Heidi Elswick.

"I think it demonstrates the kind of access that photographers had in years past," he says. "Today, any political situation that photographers see is managed, and it's almost impossible to get a 'real' moment."

Dennis Brack, who received his White House press pass in 1965, tells an anecdote about President Truman — the only president who was also a member of the WHNPA: "We created a section [in the annual WHNPA photo contest] ... it was called the President's Class, and only the presidents could enter. ... He won every year."

Compare that with President Hoover and his wife, who had a "15-foot rule" to keep photographers at bay.

"We have the best jobs in the world," says Brack. "Sure, the hours are long, and you might have to work in the rain ... but the trade-off is pretty good."

The full exhibit of historic WHNPA photographs is now on display at the Edison gallery in Washington, D.C., until February.